PEGASUS LN 2S
30
EN
Accessing the electrical terminal block and components inside the control panel
To access the electrical components inside the control panel, follow the sequence in
fig. 3. The layout of the terminals for the various connections is given in the wiring dia-
grams in the technical data section.
fig. 3 - Accessing the terminal block
Key
A
Undo the 2 self-tapping screws securing the boiler cover.
B
Lift by pressing upwards and remove the cover held to the sides of the boiler by
pins.
C
Undo and remove the two screws and the two plates holding the control panel.
D
Turn the control panel forwards.
Any additional sensitive elements of the system's control and safety devices, tempera-
ture probe, pressure switch, thermostat bulb, etc., must be located on the delivery pipe
within 40 cm of the boiler casing rear wall (see fig. 4).
Key
A
System delivery
B
System return
C
40 cm max.
fig. 4 - Delivery and return
3.6 Connection to the flue
The flue connection pipe diameter must not be less than that of the connection on the
anti-backflow device. Starting from the anti-backflow device it must have a vertical sec-
tion at least 50 cm long. Comply with the current regulations regarding installation and
sizes of the flues and connection pipe.
The diameters of the anti-backflow device collars are given in table 1.
4. SERVICE AND MAINTENANCE
4.1 Adjustments
All adjustment and conversion operations must be carried out by Qualified Personnel.
The manufacturer declines any liability for damage and/or injury caused by unqualified
and unauthorised persons tampering with the unit.
2-stage burner
The burner unit is divided into two separate parts (stages), each of which controlled in-
dependently by one or two gas valves, flame control unit and pilot burner. Partial (1st
stage) or total (1st + 2nd stage) burner ignition enables the unit to supply 2 separate pow-
er outputs according to system needs.
Burner gas pressure adjustment
The boilers
PEGASUS LN 2S
are arranged to operate on natural or liquefied gas. The
pressure setting and test are performed in the factory.
However, at first lighting, as there may be supply pressure variations, check and if nec-
essary adjust the pressure at the nozzles, respecting the values given in the technical
data table in sec. 5.3.
The operations for adjusting the pressure are performed with the boiler working, using
the pressure controls on the gas valves.
1st stage
Connect a manometer to pressure point “A” (fig. 5) located below the 1st stage gas
valve. Turn the boiler thermostat knob to maximum.
Remove the protection cap 1 (fig. 6) of the gas valves and adjust the required pressure
value at the burner by means of the screw below (see technical data table - sec. 5.3).
On 10-18 element models, adjust both 1st stage gas valves.
2nd stage
Connect a pressure gauge to pressure point "B" (fig. 5) located downstream of the 2nd
stage gas valves. Remove the protection cap 2 and adjust the required pressure value
at the burner by means of the screw below (see technical data table - sec. 5.3).
On 10-18 element models, adjust both 2nd stage gas valves.
fig. 5 - Burners
Key
V1
8 ÷ 9 Elements
V2
10 ÷ 18 Elements
Table. 2
A
The gas pressures measured at the burner gas manifold should be read at least
30 seconds after making the adjustments, i.e. when the flame has stabilised.
After the adjustment operations, light and turn the burner off 2 - 3 times with the control
thermostat and check that the pressure values are those just set; otherwise another ad-
justment is necessary to bring the pressures to the correct values.
Gas conversion
The unit can work with Natural gas (G20-G25) or liquefied gas (G30-G31) and is factory-
set for use with one of the two gases, as clearly shown on the packing and dataplate.
Whenever the unit has to be used with a different gas, a conversion kit will be required,
proceeding as follows.
From natural to liquefied gas
1.
Replace the nozzles at the main burner and pilot burner, fitting the nozzles specified
in the technical data table in sec. 5.3.
2.
Remove the small cap 3 (fig. 6) from the gas valve, screw the ignition “STEP” regu-
lator 2 (contained in the conversion kit) onto the valve and refit the cap 3 on the reg-
ulator.
3.
Adjust the burner gas pressures as described in the previous section, setting the val-
ues given in the technical data table in sec. 5.3.
4.
Operations 2 and 3 must be performed on all the valves.
5.
Apply the sticker contained in the conversion kit, near the dataplate as proof of the
conversion.
A
B
C
Type
Gas supply
pressure
mbar
Pressure at burner
Ø Nozzles
mm
A
B
G31
G20
G31
G20
G31
G20
G31
G20
PEGASUS 119 LN 2S
37
20
35
15
35
15
2.15
3.40
PEGASUS 136 LN 2S
37
20
35
15
35
15
2.15
3.40
PEGASUS 153 LN 2S
37
20
35
15
35
15
2.15
3.40
PEGASUS 170 LN 2S
37
20
35
15
35
15
2.15
3.40
PEGASUS 187 LN 2S
37
20
35
15
35
15
2.15
3.40
PEGASUS 221 LN 2S
37
20
35
15
35
15
2.15
3.40
PEGASUS 255 LN 2S
37
20
35
15
35
15
2.15
3.40
PEGASUS 289 LN 2S
37
20
35
15
35
15
2.15
3.40
A
B
1
2
A
B
1
2
1
2
V1
V2
cod. 3540T612 - Rev. 01 - 02/2015
